U.S. patent application number 14/039905 was filed with the patent office on 2014-01-30 for control system for surveillance camera.
This patent application is currently assigned to FUJIFILM Corporation. Invention is credited to Tsuyoshi OSAWA.
Application Number | 20140028844 14/039905 |
Document ID | / |
Family ID | 46930432 |
Filed Date | 2014-01-30 |
United States Patent
Application |
20140028844 |
Kind Code |
A1 |
OSAWA; Tsuyoshi |
January 30, 2014 |
CONTROL SYSTEM FOR SURVEILLANCE CAMERA
Abstract
When an anomaly occurs in an optical system circuit unit of a
surveillance camera, an error signal is transmitted to an external
communicator of a control room through a camera-side communicator.
When an error, with a special code, requiring a support service
occurs, an emergency contact button on an optical system operation
panel, which is used to control operation of the surveillance
camera, is operated. In response to the operation, a lock signal is
transmitted to the surveillance camera. Power supply to solenoids
of an image shake correction device is stopped. A correction lens
is centered on and fixed to an optical axis.
Inventors: |
OSAWA; Tsuyoshi; (Saitama,
JP) |
Assignee: |
FUJIFILM Corporation
Tokyo
JP
|
Family ID: |
46930432 |
Appl. No.: |
14/039905 |
Filed: |
September 27, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/JP2012/054393 |
Feb 23, 2012 |
|
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14039905 |
|
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Current U.S.
Class: |
348/143 ;
348/208.3 |
Current CPC
Class: |
H04N 7/183 20130101;
H04N 5/23248 20130101; H04N 5/23203 20130101; G03B 2217/005
20130101; H04N 5/23287 20130101; G03B 2205/0015 20130101 |
Class at
Publication: |
348/143 ;
348/208.3 |
International
Class: |
H04N 5/232 20060101
H04N005/232 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 31, 2011 |
JP |
2011-079259 |
Claims
1. A control system for a surveillance camera, the surveillance
camera including a housing, an imaging optical system in the
housing, and an image shake correction device for moving a
correction element, in accordance with vibration on the housing, to
correct an image shake, the correction element being included in a
part of the imaging optical system, the control system comprising:
a locking device incorporated in the housing, the locking device
centering and fixing the correction element on an imaging optical
axis; a pan and tilt mechanism for changing an orientation of the
surveillance camera supported by a mount; a camera-side
communicator incorporated in the housing, the camera-side
communicator receiving a signal from outside of the housing; and an
external communicator for transmitting a lock signal, for allowing
the locking device to operate, to the camera-side communicator from
the outside of the housing, the external communicator transmitting
a signal, for fixing the surveillance camera toward a preset fixed
point direction, to the camera-side communicator from the outside
of the housing if the orientation of the surveillance camera is in
a direction other than the fixed point direction when the lock
signal is transmitted.
2. The control system for a surveillance camera according to claim
1, wherein the camera-side communicator receives a control signal,
transmitted from the external communicator, for controlling
operation of the surveillance camera and transmits an image signal,
obtained from the surveillance camera, and an operation signal,
pertaining to operation of the imaging optical system, to the
external communicator, and the external communicator transmits the
control signal to the camera-side communicator and outputs the
received image signal to a recording device.
3. The control system for a surveillance camera according to claim
2, wherein the external communicator is provided along with an
operation panel for operating the surveillance camera and the
imaging optical system, and an operation range of the imaging
optical system operated through the operation panel is restricted
when the lock signal is transmitted.
4. The control system for a surveillance camera according to claim
3, wherein a magnification range of the imaging optical system is
restricted to a predetermined range on a wide-angle side when the
lock signal is transmitted.
5. The control system for a surveillance camera according to claim
1, wherein when power is supplied, the locking device releases a
lock on the correction element to allow the correction element to
perform image shake correction, and the locking device centers the
correction element and fixes the correction element in a centering
position when supply of the power is stopped.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Bypass continuation of
PCT/JP2012/054393 filed on Feb. 23, 2012, which claims foreign
priority to Japanese Application No. 2011-079259 filed on Mar. 31,
2011.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the invention
[0003] The present invention relates to a control system for a
surveillance camera incorporating a vibration isolator that
prevents shaking of an image due to vibration or the like.
[0004] 2. Description Related to the Prior Art
[0005] Recently, surveillance cameras or monitoring cameras, also
referred to as CCTV (Closed-circuit Television) cameras, have been
used for various purposes. For example, a camera for monitoring
ships coming in and out from a mouth of a bay uses a zoom lens as
an optical system. There is a zoom lens for a surveillance camera
with a magnification ratio, between the magnification at a
wide-angle end and the magnification at a telephoto end, of up to
50 to 60 times. The magnification at the wide-angle end is used to
monitor a wide area such as the entire mouth of the bay. The
magnification at the telephoto end is used to check the name or the
country of an incoming ship. When a camera with a high
magnification ratio shakes due to a wind or the like during imaging
on the telephoto side, the shaking is also magnified on an imaging
surface. Thus, the image shake is likely to occur.
[0006] An image shake correction device disclosed in, for example,
Japanese Patent Laid-Open Publication Nos. 2010-237251 and 9-80531
is used to prevent the image shake. As for methods for preventing
the image shake, there are an electronic correction method and a
mechanical correction method. In the electronic correction method,
image data from an image sensor is electronically processed in
accordance with the shake of a camera housing. In the mechanical
correction method, a correction lens and the like in an optical
system is moved within a plane perpendicular to an optical axis to
correct an optical path. A device according to the former method
has a simple structure, but needs to omit a part of the image data
to perform image shake correction. Hence, it is disadvantageous in
taking a sharp image. On the other hand, a device according to the
latter method has a complicated structure, but has a significant
advantage in taking a sharp image. The devices according to the
latter method are widely used in cameras for monitoring boundaries
and mouths of bays, for example.
[0007] The risk of failure of the image shake correction device
according to the mechanical correction method is far greater than
that of the image shake correction device according to the
electronic method because the image shake correction device
according to the mechanical correction method comprises
mechanically movable parts. For example, when a drive actuator goes
out of control due to oscillations or the like, an element for
correction that moves slightly within a predetermined stroke range
is pressed against a stroke end. As a result, the image quality
largely deteriorates. The surveillance camera is required to
continue the imaging as much as possible without interruption. Even
if a part of its functions is impaired by failure, the surveillance
camera is required to continue the monitoring and the recording of
images in a feasible manner until a support service for repair is
provided.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide a control
system for a surveillance camera, with an image shake correction
device, capable of continuing monitoring and recording of images
with the use of remaining functions in case of a serious failure or
anomaly that requires repair by an expert.
[0009] To achieve the above and other objects, the control system
for a surveillance camera according to the present invention
comprises a locking device, a pan and tilt mechanism, a camera-side
communicator, and an external communicator. The locking device is
incorporated in a housing. The locking device centers and fixes a
correction element on an imaging optical axis. The pan and tilt
mechanism changes an orientation of the surveillance camera
supported by a mount. The camera-side communicator is incorporated
in the housing. The camera-side communicator receives a signal from
outside of the housing. The external communicator transmits a lock
signal to the camera-side communicator from the outside of the
housing. The lock signal allows the locking device to operate. The
external communicator transmits a signal, for fixing the
surveillance camera toward a preset fixed point direction, to the
camera-side communicator from the outside of the housing if the
orientation of the surveillance camera is in a direction other than
the fixed point direction when the lock signal is transmitted. The
surveillance camera includes the housing, the imaging optical
system in the housing, and the image shake correction device for
moving the correction element, in accordance with vibration on the
housing, to correct an image shake. The correction element is
included in a part of the imaging optical system.
[0010] It is preferable that the camera-side communicator receives
a control signal, which controls operation of the surveillance
camera, from the external communicator and transmits an image
signal obtained from the surveillance camera and an operation
signal pertaining to operation of the imaging optical system to the
external communicator. It is preferable that the external
communicator transmits the control signal to the camera-side
communicator and outputs the received image signal to a recording
device.
[0011] It is preferable that the external communicator is provided
along with an operation panel for operating the surveillance camera
and the imaging optical system. It is preferable that an operation
range of the imaging optical system, operated through the operation
panel, is restricted when the lock signal is transmitted.
[0012] It is preferable that a magnification range of the imaging
optical system is restricted to a predetermined range on a
wide-angle side when the lock signal is transmitted.
[0013] It is preferable that the locking device releases a lock on
the correction element to allow the correction element to perform
image shake correction when power is supplied. It is preferable
that the locking device centers the correction element and then
fixes the correction element in a centering position when supply of
the power is stopped.
[0014] According to the present invention, the correction element
for the image shake correction is automatically centered on and
fixed to the optical axis of the imaging optical system when an
anomaly which requires the support service occurs and an operation
corresponding to the anomaly is performed. Hence, the surveillance
camera can basically continue monitoring and recording of images
before the support service is performed. An accidental interruption
of monitoring is prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The above and other objects and advantages of the present
invention will be more apparent from the following detailed
description of the preferred embodiments when read in connection
with the accompanied drawings, wherein like reference numerals
designate like or corresponding parts throughout the several views,
and wherein:
[0016] FIG. 1 is an external view of a surveillance camera of the
present invention;
[0017] FIG. 2 is a block diagram illustrating an outline of a
control system of the surveillance camera of the present
invention;
[0018] FIG. 3 is a perspective view illustrating an outline of an
image shake correction device;
[0019] FIG. 4 is a schematic view illustrating an example of a
locking device of an image shake correction element;
[0020] FIG. 5 is a flowchart illustrating an operation of the
present invention;
[0021] FIG. 6 is an explanatory view illustrating an example of a
monitor display screen during normal times;
[0022] FIG. 7 is an explanatory view illustrating an example of a
monitor display screen at the time of an error; and
[0023] FIG. 8 is an explanatory view illustrating an example of a
monitor display screen after a contact to a support service has
been made.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] As shown in FIG. 1, a surveillance camera or monitoring
camera 2 according to the present invention is placed on a mount 3.
The surveillance camera 2 is used for monitoring a mouth of a bay.
Basically, the surveillance camera 2 is used for fixed point
monitoring. An imaging optical axis is preset to be directed toward
a predetermined monitoring point. The surveillance camera 2 is set
on a pan and tilt mechanism 4. The surveillance camera 2 can change
its orientation within a limited range of 3 to 5.degree., for
example.
[0025] A housing 2a incorporates a power supply circuit, an imaging
optical system, a control circuit for the imaging optical system,
and the like. A camera unit is connected in the rear end of the
housing 2a. The camera unit incorporates a solid state image sensor
such as a CMOS sensor or a CCD image sensor and a driver circuit
for the solid state image sensor. Power used for driving the camera
unit is supplied to the power supply circuit through an underground
cable 5 and a cord routed through a support 6, the mount 3, and the
pan and tilt mechanism 4 to the power supply circuit.
[0026] The mount 3 is provided with a door 7 with a locking key.
When the door 7 is open, a power on/off switch for turning the
surveillance camera 2 on/off, an emergency contact button, and the
like appear. The emergency contact button is operated when a
support service is necessary due to serious failure or error. It is
preferable to accommodate a wireless communicator inside the door 7
so that a user can contact a control room. The control room
operates the surveillance camera 2. Images transmitted from the
surveillance camera 2 are observed and stored in the control
room.
[0027] In FIG. 2, the control room is provided with a device for
remotely controlling the surveillance camera 2 or receiving an
image signal from the surveillance camera 2. The housing 2a
incorporates an imaging optical system 10 having a zoom function or
magnification function. The imaging optical system 10 comprises a
focus lens 11, a magnification lens 12, a compensator lens 13, and
a relay lens 14, in this order from an object side. A correction
lens 15, being an element (correction element) for image shake
correction, is included in the relay lens 14. A filter 16 is
provided behind the relay lens 14. The filter 16 is inserted,
removed, and switched using a turret method.
[0028] The housing 2a incorporates an optical system circuit unit
23 for controlling the operation of the imaging optical system 10.
The optical system circuit unit 23 comprises a focusing device 17,
a zoom device or magnification device 18, a gyro sensor 19, an
image shake correction device 20, and a filter switching device 21,
each provided with an actuator. A motor 17a moves the focus lens 11
in a direction of an optical axis P. Motors 18a and 18b move the
magnification lens 12 and the compensator lens 13, respectively, in
the direction of the optical axis P. Note that the magnification
lens 12 and the compensator lens 13 can be moved separately from
each other in the optical axis direction with the use of their
respective cam grooves formed in a cam barrel for magnification.
The motor 18b is omitted when the cam barrel is rotated by the
motor 18a. Each of the above-described focusing operation and the
magnification operation is performed by manual input from an
optical system operation panel 36 provided in the control room,
which will be described below.
[0029] The image shake correction device 20 is provided with a pair
of voice coil motors 20a and 20b and a pair of solenoids 22a and
22b. The voice coil motors 20a and 20b move the correction lens 15
within a plane perpendicular to the optical axis P.
[0030] Preferably, a moving direction of the correction lens 15
moved by the voice coil motor 20a is orthogonal to that of the
correction lens 15 moved by the voice coil motor 20b. The motors
20a and 20b are driven in accordance with an image shake signal
that corresponds to the shake of the housing 2a and is obtained
from the gyro sensor 19. Thereby the correction lens 15 is moved
within the plane perpendicular to the optical axis P so as to
correct the image shake. The pair of solenoids 22a and 22b are used
to switch between a state in which the correction lens 15 is moved
to correct the image shake and a state in which the center of the
correction lens 15 is positioned to coincide with the optical axis
P and the correction lens 15 is locked into that position
(centering position).
[0031] An image sensor 24 sensitive to an infrared region can be
used in the daytime by driving a motor 21a of the filter switching
device 21 to insert an infrared cut filter as the filter 16 in an
imaging optical path as illustrated by way of example. When the
infrared cut filter is removed from the imaging optical path, the
same image sensor 24 can be used for monitoring at night, using
infrared light. When a polarizing filter is used as the filter 16,
light reflected from the surface of the sea is removed during the
daytime monitoring on a fine day, and thereby sharpness of a
monitor image is improved.
[0032] A sensor driver 25 and an image signal processing circuit 26
are incorporated as an imaging system circuit unit 27 in the
housing 2a. The sensor driver 25 drives the image sensor 24. The
image signal processing circuit 26 performs various signal
processes on an image signal obtained from the image sensor 24. The
optical system circuit unit 23 and the imaging system circuit unit
27 are electrically connected to a camera-side communicator 29. The
camera-side communicator 29 has a receiver 30 and a transmitter 31.
The camera-side communicator 29 is also accommodated in the housing
2a. A power supply circuit 33, incorporated in the housing 2a,
supplies power to the camera-side communicator 29, the optical
system circuit unit 23, and the imaging system circuit unit 27.
[0033] The control room is located remote from the surveillance
camera 2. The operation of the surveillance camera 2 is controlled
through the control room. Images produced based on the image
signals from the surveillance camera 2 are monitored and recorded
in the control room. A control system unit 35, used in the control
room, includes the optical system operation panel 36, an imaging
device operation panel 37, an image display monitor 38, and an
image recorder 39. The optical system operation panel 36 is used
for input operation to control the operation of the optical system
circuit unit 23. The imaging device operation panel 37 is used for
input operation to control the operation of the imaging system
circuit unit 27. The image display monitor 38 displays the monitor
images based on the image signals from the surveillance camera 2.
The image recorder 39 records the image data. The optical system
operation panel 36, the imaging device operation panel 37, the
image display monitor 38, and the image recorder 39 are
electrically connected to a transmitter 41 and a receiver 42. The
transmitter 41 and the receiver 42 constitute an external
communicator 40.
[0034] FIG. 3 illustrates an example of a support structure of the
correction lens 15. A pair of horizontally extending guide shafts
45a is fixed to a support frame 45. The support frame 45 is fixed
to a barrel structure (not shown) of the imaging optical system 10.
The guide shafts 45a support a slide frame 46 such that the slide
frame 46 is movable in a horizontal direction. The slide frame 46
is operationally connected to the voice coil motor 20a provided on
the fixed support frame 45. An amount of movement of the slide
frame 46 in the horizontal direction and its moving speed are
determined in accordance with the drive of the voice coil motor
20a. A permanent magnet 46b is fixed to the slide frame 46. A Hall
element 45b is provided on the support frame 45 in the position to
face the permanent magnet 46b. A position of the slide frame 46 in
the horizontal direction is detected by monitoring a signal from
the Hall element 45b.
[0035] A pair of perpendicularly extending guide shafts 46a is
disposed on the slide frame 46. The guide shafts 46a support a lens
frame 48 such that the lens frame 48 is movable in a perpendicular
direction. The lens frame 48 is operationally connected to the
voice coil motor 20b fixed to the slide frame 46. An amount of
movement of the lens frame 48 in the perpendicular direction and
its moving speed are determined in accordance with the drive of the
voice coil motor 20b. The position of the lens frame 48 in the
perpendicular direction is detected with the use of a permanent
magnet 48a fixed to the lens frame 48 and a Hall element 46c
provided on the slide frame 46. Note that, instead of the Hall
elements 45b and 46c, a PSD (Position Sensitive Device) may be used
to improve accuracy of the positional detection. The PSD detects
light from a light emitting element such as an LED fixed to each of
the slide frame 46 and the lens frame 48. Thereby, the position of
each of the slide frame 46 and the lens frame 48 is identified.
[0036] The correction lens 15 for image shake correction is fixed
to the lens frame 48. By controlling the drive of the voice coil
motors 20a and 20b, the correction lens 15 is moved in any desired
direction within the plane perpendicular to the optical axis P.
Hence, by controlling the drive of the voice coil motors 20a and
20b in accordance with the image shake signal detected by the gyro
sensor 19, the correction lens 15 is shifted to correct the shake.
The image shake on a photoelectric surface of the image sensor 24
is prevented by utilizing refraction of light rays caused by the
shifting of the correction lens 15.
[0037] Magnification information of the imaging optical system 10
needs to be taken into consideration to control the drive of the
voice coil motors 20a and 20b. A well-known means or device such as
an encoder is used to read positional information of the
magnification lens 12. The positional information is inputted to
the image shake correction device 20. An actuator for moving the
correction lens 15 is not limited to the voice coil motor. For
example, a piezoelectric element may be used.
[0038] FIG. 4 illustrates an example of a locking device that
centers the correction lens 15 on the optical axis P and fixes the
correction lens 15 in the centering position. A pin 51, protruding
toward the front, is provided on a front face of the slide frame
46. A pin 52, protruding toward the front, is provided on a front
face of the lens frame 48. The pin 51 is fixed in a position in
which the center of the pin 51 is within a vertical plane crossing
the optical axis P. The pin 52 is fixed in a position in which the
center of the pin 52 is within a horizontal plane crossing the
optical axis P. The pin 51 moves in the horizontal direction along
with the slide frame 46. A pair of stop plates 54 and 54 is
provided so as to form a space between them. The space is wider
than a predetermined maximum travel stroke.
[0039] The stop plates 54 and 54 are provided with upright pieces
54b and 54b, respectively. The upright pieces 54b and 54b face each
other. As illustrated in the drawing, a horizontally extending
guide slot is formed on each of the stop plates 54 and 54. Guide
pins, each fixed to a barrel structure portion, engage with the
respective guide slots, so that the stop plates 54 and 54 are
movable in the horizontal direction separately from the slide frame
46. Control pins 54a are implanted in the respective stop plates 54
and 54 . The control pins 54a engage with respective cam grooves
56a. The each cam groove 56a has a V-shape and formed in a control
plate 56 that is guided to move in the perpendicular direction. The
pair of V-shaped cam grooves 56a are symmetrical relative to a
vertical plane including the optical axis P.
[0040] In the illustrated state, the solenoid 22a of the image
shake correction device 20 is turned on to pull down the control
plate 56 against biasing of a spring 57. Thereby, a sufficient
space is secured between the upright pieces 54b and 54b of the stop
plates 54 and 54, allowing the pin 51 to move along with the slide
frame 46 in the horizontal direction. To center and fix the
correction lens 15 on the optical axis P at the occurrence of an
abnormal signal, the supply of power to the solenoid 22a is
stopped. When the supply of power to the solenoid 22a is stopped,
the control plate 56 goes up due to the biasing of the spring 57.
Due to operation of the cam grooves 56a, the pair of stop plates 54
and 54 moves horizontally in a direction to come closer to each
other through the control pins 54a.
[0041] When the upright pieces 54b and 54b of the respective stop
plates 54 and 54 come close to each other, the pin 51 is pressed
toward the center by one of the upright pieces 54b regardless of
the position of the pin 51 in the horizontal direction. Eventually,
the pin 51 is held and fixed between the upright pieces 54b and
54b. When fixed, the pin 51 is located immediately below the
optical axis P. The pair of stop plates 54 and 54 and a mechanism
to move the stop plates 54 and 54 in the horizontal direction
constitute a locking device of the horizontal direction. The
locking device of the horizontal direction places the center of the
correction lens 15 on the optical axis P and locks the correction
lens 15 to the optical axis P in the horizontal direction.
[0042] The pin 51 of the slide frame 46 is provided in a position
within a vertical plane crossing the optical axis P. The pin 52 on
the lens frame 48 differs from the pin 51 only in that the pin 52
is located within a horizontal plane crossing the optical axis P.
Hence, when the above-described locking device of the horizontal
direction is rotated 90.degree. in the counter-clockwise direction
and the pair of stop plates moves in the perpendicular direction
relative to the barrel structure portion, it is used as the locking
device of the perpendicular direction. In the locking device of the
perpendicular direction, the control plates are moved in the
horizontal direction to move the pair of stop plates in the
perpendicular direction. The pin 52 is located between the upright
pieces integrated with the respective stop plates. Eventually, the
pin 52 is positioned and fixed in a position within the horizontal
plane crossing the optical axis P.
[0043] Note that, in the above-described structure, when the slide
frame 46 moves in the horizontal direction such that the pin 51 is
located away from the immediate underneath of the optical axis P,
the pin 52 may be located outside of moving paths of the pair of
upright pieces provided integrally with the stop plates of the
locking device of the perpendicular direction. In this case, the
pin 52 cannot be located between the pair of upright pieces only by
operating the locking device of the perpendicular direction. To
prevent this, the pair of upright pieces for positioning the pin 52
in the perpendicular direction is extended sufficiently relative to
a moving range of the slide frame 46 in the horizontal direction.
When a centering process is performed, first, the pin 51 is used to
position the slide frame 46 in the horizontal direction. Next, the
pin 52 is used to position the lens frame 48 in the perpendicular
direction. As for the lock mechanism of the lens frame 48 in the
perpendicular direction using the pin 52, the lock mechanism
illustrated in FIG. 4 may be rotated 90.degree. in the
counter-clockwise direction and attached not to the barrel
structure portion but to the slide frame 46.
[0044] When the pins 51 and 52 are positioned as described above,
the correction lens 15 with the lens frame 48 is centered on the
optical axis P such that the center of the correction lens 15
coincides with the optical axis P, and the correction lens 15 is
mechanically fixed in the centering position. Note that the
actuator of the locking device is not limited to the solenoid. A
motor or the like may be used as the actuator of the locking
device. The centering of the pins 51 and 52 may be performed by
supplying the power to the actuator(s). However, it is advantageous
that the center of the correction lens 15 is located on and locked
to the optical axis by stopping the supply of power to the
actuator(s) in consideration of an unforeseen situation such as
failure or anomaly of the power supply circuit 33 or an outage.
[0045] Referring to a flowchart in FIG. 5, an operation of a
control system for the above-described surveillance camera is
described. During normal monitoring, the surveillance camera 2 is
controlled as desired by a command from the control room.
Basically, the surveillance camera 2 is used for the fixed point
monitoring. The orientation of the surveillance camera 2 is preset
toward the head of a pier in the mouth of the bay, for example.
When a command for the fixed point monitoring is inputted from the
optical system operation panel 36, the mount 3 of the surveillance
camera 2 is controlled through the transmitter 41 of the control
room and the receiver 30 on the camera-side such that the
predetermined fixed point is located at the center of a screen.
[0046] Panning and tilting are performed within limited ranges.
Magnification of the imaging optical system 10 is changed through
input operation from the optical system operation panel 36. FIG. 6
illustrates an example of an image taken with the surveillance
camera 2 and displayed on the image display monitor 38 of the
control room. The image is taken with the imaging optical system 10
with the magnification on the telephoto side. Date and time data 60
and a magnification scale 61 are displayed together with the image
on the monitor screen. These images are recorded by the image
recorder 39 as necessary or constantly.
[0047] When an anomaly occurs in the surveillance camera 2, an
error check function in the surveillance camera works and the
camera-side transmitter 31 transmits an error signal. The error
signal includes an error code identifying the type of the error.
The receiver 42 receives the error signal together with an image
signal from the surveillance camera 2. As shown in FIG. 7, the
image display monitor 38 in the control room displays an error code
62.
[0048] In this example, an abnormal operation error of the imaging
optical system 10 has caused. The error code includes a special
code "SS", denoting that the support service is necessary. In this
case, a warning, in which the error code 62 expressed in capital
letters blinks at the center of the monitor screen, is displayed.
This error code 62 represents, for example, an abnormal operation
of the image shake correction device 20 and corresponds to an error
which results in a major damage to a drive system of the correction
lens 15 if the image shake correction device 20 is used
continuously without repair and the repair of which is anticipated
to be extremely difficult. Note that, in the case of a normal error
code not including the special code, a normal maintenance operation
is performed while the surveillance camera 2 is used
continuously.
[0049] When a warning illustrated in FIG. 7 is displayed, an
operator in the control room checks the warning and operates an
emergency contact button on the optical system operation panel 36.
When necessary, the operator directly contacts the support service
department through a wireless communicator or the like. When the
emergency contact button is operated, a lock signal is transmitted
from the optical system operation panel 36 to the transmitter 41.
The camera-side receiver 30 receives the lock signal. The lock
signal is transmitted to the optical system circuit unit 23. A
locking process of the correction lens 15 is performed when the
imaging optical system 10 is used in an image shake correction
mode. Note that, when the imaging optical system 10 is not used in
the image shake correction mode, the solenoids 22a and 22b are in
an OFF state. Namely, the correction lens 15 remains fixed on the
optical axis.
[0050] The locking process is performed by stopping the supply of
power to the pair of solenoids 22a and 22b of the image shake
correction device 20. The correction lens 15 is centered on the
optical axis P and fixed in the centering position. Concurrently
with the locking process, the imaging optical system 10 is
automatically set to the wide-angle end if the imaging optical
system 10 has been set to the telephoto side. As for the imaging
optical system 10 with normal magnification function of 50 to 60
times, its magnification range is restricted to approximately 5
times from the wide-angle end. The image display monitor 38
displays a screen illustrated in FIG. 8. The screen allows the
operator to correctly understand the circumstances such as "the
occurrence of error with the special code", "the contact to the
support service has been made", and "the restriction on the
magnification function".
[0051] As described above, a special code is provided in advance
for an urgent error that needs to be repaired immediately. When
such error occurs, the control room responds to it immediately.
When the contact to the support service is made through the optical
system operation panel 36 to handle the error, the lock signal is
automatically transmitted to the transmitter 41 and the correction
lens 15 for the image shake correction is automatically returned
and locked in the centering position on the optical axis. After
that, without being aware of such complicated operation, the user
can continue the monitoring while utilizing basic functions
required for the surveillance camera 2 for the fixed point
monitoring. Although the image shake correction device 20 cannot be
used, a large or apparent image shake is not likely to occur
because the magnification of the imaging optical system 10 is
changed to that on the wide-angle end side. If an image with high
image magnification is necessary, a substantially sharp image is
obtained by enlarging the image using image processing.
[0052] Note that, a trigger for the locking process of the
correction lens 15 is not limited to the above-described operation
of the emergency contact button of the optical system operation
panel 36 in the control room. For example, a commonly used mobile
phone may be used to contact the support service. The locking
process of the correction lens 15 may be initiated automatically by
receiving a radio signal produced by operating the mobile phone. It
is effective to provide the emergency contact button inside the
door 7 of the mount 3 because a user visiting and inspecting the
surveillance camera may find a trouble which needs the support
service. The pressing operation of the emergency contact button is
transmitted to the control room through the camera-side
communicator 29 and the external communicator 40. Thereby a similar
sequencing process is performed. The emergency contact button
inside the door 7 of the mount 3 may have a function equivalent to
that of the emergency contact button of the optical system
operation panel 36.
[0053] Various changes and modifications are possible in the
present invention and may be understood to be within the present
invention.
* * * * *